After a series of complaints from residents of a Paris apartment building about an unpleasant odor emanating from one of the units, authorities break down the door to discover the lifeless body of Anne, adorned with fresh flowers, laying on a bed.
Several months prior to this tragic moment, Anne and her husband Georges, both octogenarian piano instructors, attend a captivating performance by Alexandre, one of Anne's former students. Upon returning home, they discover that an attempted break-in has occurred in their apartment. The following morning, as the couple enjoys breakfast, Anne suffers a stroke, plunging her into a catatonic state unresponsive to Georges's calls. Just as Georges prepares to seek help, Anne regains consciousness, unwittingly unaware that a stroke had transpired. Initially, she resists medical intervention until she realizes she cannot pour her own drink.
Following her surgery aimed to unblock a carotid artery, complications arise, leaving Anne paralyzed on her right side and bound to a wheelchair. She extracts a promise from Georges, urging him not to admit her back into a hospital or nursing care. In turn, Georges becomes her dedicated caretaker, though growing increasingly weary. One fateful day, after seemingly attempting suicide by leaping from a window, Anne expresses her desire to no longer continue living.
During a visit from Alexandre, Anne brightens up momentarily, dressing elegantly and engaging in a lively chat, which instills a glimmer of hope in Georges about her recovery. Unfortunately, that hope is short-lived as Anne suffers a second stroke that severely affects her mental faculties, stripping her of coherent speech. Georges, steadfast in his caregiving role, begins hiring a nurse three days a week to help manage Anne's condition. Meanwhile, their daughter Eva urges Georges to consider professional care, but he steadfastly refuses to break the promise he made to Anne. Eventually, he hires a second nurse but dismisses her upon discovering her mistreatment of Anne.
In a poignant moment, Georges sits beside Anne's bed, recounting stories from his childhood to soothe her. However, as he reaches the tale's conclusion, he tragically takes a pillow and smothers her. Afterward, Georges returns home with arms full of flowers, carefully washing and trimming them. He selects a dress from Anne's wardrobe and composes a heartfelt letter, sealing the bedroom door and catching a pigeon that has entered through the window. In his letter, Georges explains that he has set the pigeon free. Engaging in a bittersweet reverie, he imagines Anne bustling about the kitchen, calling for him to fetch her a coat, and he follows her out the door.
The film culminates in a haunting return to the opening scene, with Eva sitting alone in the living room, wandering through the now silent and empty home.
